It also reveals reasons behind the closure of the desk – that as the number of UFO sightings surged between 2007 and 2009, valuable MoD resources were being diverted to handling the claims.

Former dDefence minister Bob Ainsworth was told in 2009 that:

“In more than 50 years, no UFO sighting reported to the department has indicated the existence of any military threat to the UK; there is no defence benefit in Air Command Secretariat recording, collating, analysing or investigating UFO sightings; (and) the level of resources devoted to this task is increasing in response to a recent upsurge in reported sightings, diverting staff from more valuable defence-related activities.”

People at home can … draw their own conclusions about whether the truth is in these files or still out there.Dr David Clarke

Up until 2007 the Ministry of Defence was receiving around 150 reports of UFO sightings a year. However, this doubled in 2008, and shot up again to more than 600 in 2009.

There are a number of reasons that could be behind the surge in UFO sightings, and whilst some may hope it is because our intergalactic neighbours have decided to visit more frequently, Dr David Clarke, who has been behind the release of files, says the answer is likely to be more mundane.

“Many of the sighting accounts, such as formations of orange lights moving slowly across the sky, describe the appearance of Chinese lanterns even though people did not recognise them at the time,” he said.

“But that is not the only explanation. Ironically there is evidence that some people were encouraged to report their observations to the MoD and to the press which could be a direct result of increased public awareness during the period that the first UFO files were being released by the National Archives.

“I believe this demonstrates that UFOs are very much a social phenomenon.”

He added: “The last files from the UFO desk are now all in the public domain. People at home can read them and draw their own conclusions about whether the truth is in these files or still out there.”

What’s in the files?

The files are a mixture of freedom of information requests, internal department correspondence, sighting reports and MoD’s responses to those reports.

A large number of the reports, in keeping with Dr Clarke’s “Chinese lanterns” theory, were of orange balls in the sky, sometimes in groups and moving “in formation”.

The location for the sightings ranges from the tip of Cornwall to the Scottish highlands. The majority of reports over 2008 and 2009 came from London, though there were also large numbers of reports from West Yorkshire, Kent, Essex, West Sussex and Cornwall (see map, below).

Amongst the sighting reports are a letter from a child, in which it is asked: “Please tell me if living things live outside our planet. I would like to know because me and my father have seen little aircraft in the sky.”

The response from the RAF, who received the letter, was: “It is an interesting question and we remain totally open-minded about it, but we don’t know of any evidence to prove life exists in outer space.” The RAF also sent the child some “goodies”.

Various letters to the UFO desk refer to the Rendlesham incident, sometimes known as “Britain’s Roswell”, which was when there were various reports of lights in the sky over Rendlesham Forest in Surrey in 1980.

Correspondence released by the MoD often suggests the department was not taking the incident seriously enough. The MoD’s rather exasperated response can be seen below.

The majority of the reports occured in the summer, and people often reported the sightings taking place whilst they were walking the dog, having a cigarette, were out in the countryside, or in one case, were relaxing in a hot tub.

One example is a man who claimed he saw spaceships whilst camping in 2007. The witness said they were moving quite slowly across the sky near Cardiff, and then abducted his dog, car and tent (see below).

Another man, from Carlisle, said that he saw a UFO, and that now an alien was living in his house – moving things around.

Another, very persistent, ‘ufologist’ regularly contacted the desk between 2007 and 2009 demanding contact with high-level members of staff, including the defence secretary, so that he could discuss his idea for a weapon to shoot down UFOs (see below).

Sightings were reported the length and breadth of the country, and from overseas. They included sightings at landmarks, such as Stonehenge and the Houses of Parliament.

The documents released also include a number of FOI requests – including one from a man asking if there had ever been a sighting of a UFO on the 24 December, Christmas Eve.

If anyone does make contact with a UFO on this date, especially if the object is pulled by reindeer and driven by a jolly fat man, we request you say that Channel 4 News has been good all year.